Background: Four-dimensional computed tomography (4D-CT) improves the precision of pre-operative localization of hyperfunctioning parathyroid glands (HPGs).

Objective: To analyze the role of pattern enhancement in 4D-CT imaging in hyperparathyroidism for differentiating HPGs from surrounding tissues for precision pre-operative localization of HPGs.

Materials and Methods: The present retrospective study was conducted in patients who underwent 4D-CT scan of the parathyroid at the Department of Radiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand between January 2013 and October 2016. Lesions were plotted for pattern enhancement, and mean Hounsfield units (HUs) of HPGs, lymph nodes, thyroid nodules, and thyroid glands were measured and analyzed.

Results: Twenty-seven patients with 119 lesions were included. Significant difference was observed between both parathyroid adenoma and hyperplasia and thyroid gland during non-contrast phase and delayed 90-second phase. Attenuation value of less than 60 HUs in pre-contrast phase could differentiate HPGs from thyroid gland with 60% sensitivity and 85% specificity. Sensitivity of 4D-CT was 100% (95% Cl 73.5 to 100) for localization of all HPGs.

Conclusion: Integration of clinical history data, conventional imaging, and 4D-CT imaging could improve differentiation of HPGs from surrounding tissues, thereby improving the precision of HPG localization during minimally invasive parathyroidectomy.

Keywords: Thailand, 4D CT pattern enhancement, Parathyroid lesions, Preoperative localization, Hyperparathyroidism

Received 6 Aug 2018 | Revised 24 Jan 2019 | Accepted 6 Feb 2019